Answer:
37.5
Step-by-step explanation:
if it decreases by 1/2 every 8 hours;
( 3×8= 24)
the first 8 hours 1/2×300 =150 gram
the second 8 hours(16 hours) = 1/2×150=75 gram
the third 8 hours(24 hours) = 1/2×75= 37.5gram
C
It's because Magnesium-27 is 8 hours which makes the 300/8=37.5
